Colorimetric Concurrent Determination of Ultra-Trace Amounts of Pilocarpine and Timolol as Anti-Glaucoma Drugs in Binary Mixtures Using a Multivariate Calibration Approach Based on the Aggregation of Gold Nanoparticles.

A colorimetric method using AuNPs was proposed. The PLS method was coupled with a colorimetric method for the ultra-trace simultaneous estimation of PIL and TIM in binary mixtures. Ultra-trace amounts of PIL and TIM were also determined in biological samples. The proposed method is simple, fast, and less expensive than chromatography methods.